1. Field of the Invention
The present invention relates to a dicing machine and method enabling reduction of chipping and cracking both of which are caused during dicing a semiconductor wafer.
2. Description of the Related Art
Conventionally, a semiconductor device having a circuit formed on a semiconductor wafer is generally subjected to dicing using a dicing blade which rotates at high speed. However, in this method, heat generates when cutting the wafer by using the dicing blade, so during the dicing, the cutting is performed while supplying cooling water to a cutting portion to suppress the heat generation.
In the following, an example of a conventional dicing method will be described with reference to the drawings. FIG. 5 shows a conventional dicing method, and is a side view of a main portion of a dicing device. There are provided a semiconductor wafer 1, a dicing blade 2, a cooling water 4, a dicing tape 5, and a cooling water nozzle 8. The dicing blade 2 rotates at several tens of thousands rpm to cut the semiconductor wafer 1 which is an object to be machined. At this time, in order to eliminate the heat generated during the cutting, the wafer is cut while supplying the cooling water 4 to the blade. However, the cooling water is flung away from the rotating dicing blade due to a centrifugal force. Therefore, it is difficult to supply a sufficient amount of water to a cutting point. Thus, there is a problem in that chipping is caused in an end surface of the semiconductor device (semiconductor chip) after the dicing.
In order to solve the problem, there has been developed various dicing methods.
For example, JP 06-85054A discloses a technique of suppressing ruptures, chipping, and cracking caused at the time of dicing the wafer by providing a mechanism including a porous blade used as a dicing blade, for emitting pure water or air from an inside of the blade, to thereby prevent clogging of the blade.
JP 06-5700 A discloses a dicing method in which the dicing blade is sandwiched from both sides thereof by flanges, and pure water is ejected from gaps between the dicing blade and the flanges. However, in this method, since the cooling water is directly supplied to the cutting point, an excessive force is exerted on the semiconductor chip, causing flapping of the semiconductor chip, and chipping occurs in the semiconductor chip.
JP 2000-349046 A discloses a method of supplying the cooling water in which a force to be applied to the semiconductor chip is devised to reduce the chipping.
JP 06-13460 A discloses a dicing method in which the cooling water nozzle is provided not only in the vicinity of the cutting portion but also on a blade outer peripheral surface, thereby elongating a life of the blade and keeping the chipping to a minimum.